...Stoichiometry ________________________________________ Stoichiometry is simply the math behind chemistry. Given enough information, one can use stoichiometry to calculate masses, moles, and percents within a chemical equation. ________________________________________ ________________________________________ What is a Chemical Equation? In chemistry, we use symbols to represent the various chemicals. Success in chemistry depends upon developing a strong familiarity with these basic symbols. For example, the symbol "C"represents an atom of carbon, and "H" represents an atom of hydrogen. To represent a molecule of table salt, sodium chloride, we would use the notation "NaCl", where "Na" represents sodium and "Cl" represents chlorine. We call chlorine "chloride" in this case because of its connection to sodium. You should have reviewed naming schemes, or nomenclature, in earlier readings. A chemical equation is an expression of a chemical process. For example: AgNO3(aq) + NaCl(aq) ---> AgCl(s) + NaNO3(aq) In this equation, AgNO3 is mixed with NaCl. The equation shows that the reactants (AgNO3 and NaCl) react through some process (--->) to form the products (AgCl and NaNO3). Since they undergo a chemical process, they are changed fundamentally. Often chemical equations are written showing the state that each substance is in. The (s) sign means that the compound is a solid. The (l) sign means the substance is a liquid. The (aq) sign stands for aqueous in water and means...
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...Laboratory 3: Molarity Of Saline Solution Note: Lab reports are to be completed by each student individually and in their own words Data: Please write your observations about the appearance of the solution. 1. Normal Saline Mass of NaCl: .9/100 ml x 100= .009 .009x100=.9 Observation: clear, completely dissolved 2. Nasal Irrigation Saline Mass of NaCl: 1.1g Mass of NaHCO3: .3g Observation: clear, completely dissolved, when mixing I was a little cloudy 3. Nasal Irrigation Saline 29.7 Observation, This solution was very cloudy with bubbles, did not dissolve all the way Results: 1. Determine the molar mass of NaCl. Show the workup. Na= 23 plus C= 35 = 58 NaCl molecules 58g/m NaCl 2. Determine the molarity of the two solutions you prepared in terms of NaCl. Show the workup. (a) Normal Saline - Molarity of NaCl M= .9 mole NaCl / 0.1 L solution= 9m NaCl (b) Nasal Irrigation Saline - Molarity of NaCl 118ml = 0.118L M= 1.1g/mole NaCl / 0.118L solution = 9.322 M NaCl (c) Nasal Irrigation Saline - Molarity of NaHCO3 M= .3 mole NaHCO3 / o.118L = 2.54 M NaHCO3 3. The University of Wisconsin recommends that if stinging or burning occurs, than individuals should cut the amount of salt in half for the solution and decrease frequency of use to every other day. How does that affect the concentration of the solution? When adding less salt it make the solution to become more dilute solution...
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...FISH 503 Advanced Limnology (University of Idaho, Moscow Idaho Cam pus) Oxygen Module Winkler titration lab Goal: To familiarize the participants with the Winkler titration of oxygen determination in water; understand principles of the underlying chemistry; to understand standardization procedures of chemical solutions; perform sodium thiosulfate standardization; perform Winkler titrations; examine experimenter error and intra-experimenter error. Examine “kits”. Outcomes: Ability to determine under what conditions Winkler chemistry is appropriate for determination of DO in water; ability to relate details of chemical reactions to and knowledge of indirect determinations; perform titrations and calculate titration standards, as well as mass of DO in samples; assess individual and among individual errors associated with method. General description: You have received a new O2 meter that the person giving to you ensures is ‘perfectly calibrated’ and ‘ready-to-go’. You are heading out on a one-shot chance to sample in the arctic, are you going to trust this person to have gotten it right. How do you check that your probe is actually giving you a believable number (yes does the light in the fridge really turn off when yo close the door?) You will find out in this lab how to check your sensor. Your tasks: 1) Familiarize yourself with the Winkler titration chemistry so you know what you are doing once you get your hands on the bottles and chemicals. 2) Standardize the Sodium thiosulfate...
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...Background: Acids are substances that are characterized by their ability to donate protons (H+) to other substances in a solution. Acids can be strong or weak. Weak acids do not ionize completely and are found in everyday substances. Acidity is a measure of the amount of dissolved hydrogen ions in a solution. The greater the number of hydrogen ions in a solution, the more acidic the solution. Strong acids donate hydrogen ions in water, to a much greater extent than weak acids. Bases are substances that are characterized by their ability to accept protons or produce hydroxide ions (OH-) in an aqueous solution. As for acids, the difference in strength of bases directly relates to the degree in which hydroxide ions are formed by the base in water. Like strong acids, strong bases are also dangerous chemicals. Weak bases are found in many everyday items. When feeling the consistency of a base, it feels slippery because it degrades the fatty acids and oils in the skin on contact. However, due to the possibility that an acid or a base could be very dangerous to human tissue, never experiment with an acid or base by tasting or touching it. To determine if a substance is an acid or a base, a pH scale may be used. pH is a measure of the concentration of hydrogen ions in a substance. The equation for pH is: pH = -log [H+]. The logarithm for pH is based on a scale of 10. As pH is a negative logarithm, the pH of a substance increases as the concentration of hydrogen ions decreases. For...
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...Chemistry Modern Analytical Chemistry David Harvey DePauw University Boston Burr Ridge, IL Dubuque, IA Madison, WI New York San Francisco St. Louis Bangkok Bogotá Caracas Lisbon London Madrid Mexico City Milan New Delhi Seoul Singapore Sydney Taipei Toronto McGraw-Hill Higher Education A Division of The McGraw-Hill Companies MODERN ANALYTICAL CHEMISTRY Copyright © 2000 by The McGraw-Hill Companies, Inc. All rights reserved. Printed in the United States of America. Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a data base or retrieval system, without the prior written permission of the publisher. This book is printed on acid-free paper. 1 2 3 4 5 6 7 8 9 0 KGP/KGP 0 9 8 7 6 5 4 3 2 1 0 ISBN 0–07–237547–7 Vice president and editorial director: Kevin T. Kane Publisher: James M. Smith Sponsoring editor: Kent A. Peterson Editorial assistant: Jennifer L. Bensink Developmental editor: Shirley R. Oberbroeckling Senior marketing manager: Martin J. Lange Senior project manager: Jayne Klein Production supervisor: Laura Fuller Coordinator of freelance design: Michelle D. Whitaker Senior photo research coordinator: Lori Hancock Senior supplement coordinator: Audrey A. Reiter Compositor: Shepherd, Inc. Typeface: 10/12 Minion Printer: Quebecor Printing Book Group/Kingsport Freelance cover/interior designer: Elise Lansdon Cover image: © George Diebold/The...
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...Name______________________________________________ IB Guide to Writing Lab Reports Standard and Higher Level Chemistry 2010-2011 Table of Contents page 1 Explanations, Clarifications, and Handy Hints page 2 - 13 IB Laboratory Evaluation Rubric page 14 - 15 Formal Lab Report Format page 16 Error Analysis Types of Experimental Errors page 17 Error Analysis: Some Key Ideas page 18 Precision and Accuracy in Measurements A Tale of Four Cylinders Assessment of Errors and Uncertainties in IB Lab Reports Explaining Terms and Concepts in Error Analysis page 19 - 20 page 21 Mathematics of Evaluating Accuracy and Precision page 26 - 27 Rejection of Data page 28 More Examples of Propagating Error page 29 - 31 page 22 - 25 Typical Instrumental Uncertainties page 32 Checklist for Writing IB Lab Reports page 33 - 34 Please read carefully and keep this handy reference for future use in writing exemplary lab reports. Page 1 IB Guide to Writing Laboratory Reports Explanations, Clarifications, and Handy Hints The nature of science is to investigate the world around you. An inquiring mind is essential to science. Experiments are designed by curious minds to gain insight into wonder-producing phenomena. Hopefully, this process of designing experiments, doing experiments, thinking about experimental results, and writing lab reports will tremendously benefit YOU! IB Chemistry is the challenge you have chosen...
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...UTAR FHSC1214 Fundamentals of Cell Biology Trimester 1 How YOU can do well in BIOLOGY Follow the 4A’s and you can expect A’s. A ttitude • Attend ALL lectures, tutorials and practicals on time without fail. • Be attentive in class and revise your notes after class while the topic is still fresh in your mind. Why waste time re-reading 2-3 months later? • Do your assignments faithfully as they carry marks for the finals. • Come prepared for lessons (i.e. read up beforehand). • Read up beforehand before attending lectures so that you won’t be lost and wasted hours of your life week after week. • Why stress yourself out if you can avoid it? Do NOT count on last minute revision for tests and examinations, as it will be too late to catch up and seek help in areas where you may find confusing or unclear of. • Why panic before exams because you can’t find this or that? Keep separate files for lecture, tutorial and practical. File up the respective notes systematically so that you do not lose them along the semester. • Do you expect the lecturer/ tutor to be available all the time to answer your questions? It is YOUR responsibility to take the initiative to clear your doubts or satisfy your curiosity to understand certain scientific phenomena by reading up on the relevant topics. A Based on a true story… A professor at the National University of Singapore recounts how on one occasion a student consulted him days before the exam. Student:...
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...Studies VII Practical 9 Cell Biology Studies IX Practical 10 Cell Biology Studies X - Experiment Description Page Writing of Lab Reports Identification of Biomolecules 5 13 Identification of Unknown Carbohydrate Solutions and Investigation of Action of Saliva and HCl in Carbohydrate Solution at Two Different Temperatures Investigation of the Effects of Catalase Concentration on Hydrogen Peroxide Decomposition 20 Synthesis of Starch Using an Enzyme Extracted from Potato Tuber Investigation of the Effects of Different Catalytic Conditions on Hydrogen Peroxide Decomposition Microscopy 27 Practical 6 Cell studies II Practical 7 Cell studies III Extraction of Cell Organelles by Cell Fractionation Determination of Solute Potential of Potato Cell Sap 47 Practical 8 Cell studies IV Effects of Different Treatments on Stained Potato Cells 64 Practical 9 Energetics I Respiration of Germinating Beans 67 Microscopic Examination of Cells at Various Stages of Plant Mitosis and Meiosis DNA, Mitosis and Meiosis Modelling 71 Respiration of Yeast 93 Practical 3 Enzyme studies I (Experiment 1) Optional: Practical 3 Enzyme studies I (Experiment 2) Practical 4 Enzyme studies II Practical 5 Cell studies I - - Practical 10 Energetics II Lab manual version 6_201505 FHSB1214 Biology I & FHSC1214 Fundamentals of Cell...
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...Studies VII Practical 9 Cell Biology Studies IX Practical 10 Cell Biology Studies X - Experiment Description Page Writing of Lab Reports Identification of Biomolecules 5 13 Identification of Unknown Carbohydrate Solutions and Investigation of Action of Saliva and HCl in Carbohydrate Solution at Two Different Temperatures Investigation of the Effects of Catalase Concentration on Hydrogen Peroxide Decomposition 20 Synthesis of Starch Using an Enzyme Extracted from Potato Tuber Investigation of the Effects of Different Catalytic Conditions on Hydrogen Peroxide Decomposition Microscopy 27 Practical 6 Cell studies II Practical 7 Cell studies III Extraction of Cell Organelles by Cell Fractionation Determination of Solute Potential of Potato Cell Sap 47 Practical 8 Cell studies IV Effects of Different Treatments on Stained Potato Cells 64 Practical 9 Energetics I Respiration of Germinating Beans 67 Microscopic Examination of Cells at Various Stages of Plant Mitosis and Meiosis DNA, Mitosis and Meiosis Modelling 71 Respiration of Yeast 93 Practical 3 Enzyme studies I (Experiment 1) Optional: Practical 3 Enzyme studies I (Experiment 2) Practical 4 Enzyme studies II Practical 5 Cell studies I - - Practical 10 Energetics II Lab manual version 6_201505 FHSB1214 Biology I & FHSC1214 Fundamentals of Cell...
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...CHM 1101 Introductory Chemistry Dawn Fox Medeba Uzzi August, 2007 Compiled and edited by Medeba Uzzi Authors’ Note This document is an initiative by the authors in an attempt to deal with what they think may be one of the reasons contributing to the relatively high failure rate in the introductory Chemistry course (CHM 1101) at the University of Guyana. It was brought to our attention that many first year students taking CHM 1101 are unable to efficiently cope with the frenetic pace of the Semester system and even less able to deal comprehensively with the large content in CHM 1101. It is hoped that by providing this paper, students will not need to make lots of notes in lectures and so they can focus on grasping the concepts taught. The document is meant to be a guide to the topics covered in CHM 1101 and is by no means exhaustive. Students are still required to attend classes regularly and punctually and to engage meaningfully in lectures and tutorials. Further, supplemental reading of these topics in any good General Chemistry text is expected. Dawn Fox Medeba Uzzi 2 SECTION 1 – Modules A – D: section deals with the foundation for chemistry. It introduces students to matter & its classification, Atom & its structure, Periodic table and chemical rxns. Introduction to Science and Measurement What is Chemistry? – Chemistry is the study of matter and its transformations Natural sciences refer to the systematic study of the natural world (our...
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